Intek RheoVac 940 User Manual
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stamp by default in a “M/DD/YY HH:MM” format). You may prefer to reformat these cells to
“M/DD/YY HH:MM:SSp/m” to display time to the nearest second in am/pm format. Once in your
desired format, you may construct trend graphs using your spreadsheet or other analysis program. An
Excel macro file is included to automatically format the raw downloaded or archived data.
3.5 CUSTOM SOFTWA RE
Custom software may be developed by the user to receive and archive RheoVac data into a computer
system. The electronics has a serial data protocol of 9600 baud, no parity check, eight data bits and one
stop bit (i.e., 9600,N,8,1). Each transmitted group of data is sent in a standard ASCII coded format
representing each process variable value, instrument identification and status information.
The data stream consists of 13 fields, followed by a carriage return <RETURN>. The first ten fields,
nine bytes each, are the process values. Following the process variables are the RheoVac serial number,
nine bytes, the process identification tag number, 15 bytes, and the RheoVac system status, seven bytes.
The data stream is then ended by a single <RETURN> byte (ASCII code 13). The total number of bytes
transmitted in each data stream is 122 bytes including the trailing <RETURN>. This data group is sent
about once every three seconds. Table V shows the field names and number of bytes in one data stream.
TABLE V. Serial Output Data Stream
(A CFM )
Sp . V ol.
W ater to
A ir Flo w
(S CFM )
< C R >
Each of the first ten process values are sent in the fixed decimal format of XXXX.XXXX with leading
and trailing zeros inserted to maintain the nine character length. The next three fields are ASCII text
strings followed by the <RETURN>. Example: The nine bytes for an air in-leak of 10.0 SCFM would
be: 0010.0000, or 48,48,49,48,46,48,48,48,48 ASCII.